Industrial truck



Nov. 24, 1953 E. R. BACKOFEN ET AL 5 INDUSTRIAL TRUCK 5 Sheets-Sheet 1Filed July 21, 1950 INVENTORS. RYAN BACKOFEN ATTYS.

ELMER J. DUNHAM SIDNEY R. SKELLENGER BY Nov. 24, 1953 E. R. BACKOFEN ElAL ,32

INDUSTRIAL. TRUCK 5 Sheets-Sheet 2 Filed July 21 1950 w R NF INVENTORS.RYAN BACKOF'EN ELMER J. DUNHAM SIDNEY R. SKELLENGER BY z ATTYS.

E. R. BACKOFEN ET AL Nov. 24, 1953 INDUSTRIAL TRUCK 5 Sheets-Sheet 3Filed July 21, 1950 INVENTORS- E. RYAN BACKOFEN ELMER J. DUNHAM SIDNEYR. SKELLENGER BY firm. W W

ATTYS.

Nov. 24, 1953 E. R. BA'CKOFEN ET AL 2,660,325

INDUSTRIAL TRUCK 5 Sheets-Sheet 4 Filed July 21, 1950 NVENTORS. E. RYANBACKOFEN ELMER J. DUNHAM SIDNEY R. SKELLENGER BY fl/uuw,

ATTYS.

Nov. 24, 1953 BACKOFEN Er AL 2,660,325

I INDUSTRIAL TRUCK Filed July 21, 1950 5 Sheets-Sheet 5 INVENTORS.

E. RYAN BACKOFEN ELMER J. DUNHAM SIDNEY R. SKELLENGER ATTYS.

Patented Nov. 24, 1953 INDUSTRIAL TRUCK .E.'Ryan=rBackofen,' Elmer J.Dunham, and Sidney R. Skellenger, Battle Creek, Mich assignors to ClarkEquipment Company, Buchanan, Mich.,

a corporation of Michigan Application July 21, 1950, Serial No. 175,264

12 Claims. .1

Our invention relates generally to industrial trucks and, morespecifically, is directed to an industrial truck having load supportingmeans, as, for example, in the formof lift forks'or an apron mounted ona load elevating and supporting carriage, andwithwhich a mechanism isprovided for'pushin'g a load off 'ofithe load supporting means.

.The present inventionv constitutesv an improvement in industrial trucksdisclosed in the copending, joint application of Elmer J .Dunham andAlfred Wayne Gunning, .Serial No. 80,736, "filed MarchlO, 1949,nowPatent No. 2,6(21331.

The mechanism of our present invention com-- prises primarily avertically extending'load engaging rack which is adapted vfor lengthwisemovement with respect tohorizontally extending load-supporting meanscarried by the load supporting carriage of an industrial truck. The rackmay be actuated through linkage means pivctally mounted between avertical supporting.memher, carried by 'the load supporting scarriage,and the load engaging rack under the influence "of "hydraulic piston andcylinder .meansconnected 'J'to the linkage means'fortpu'shing all'oad-offofi't'he i load :supporting. means. lhe linkage. means i of thepusher' mechanism is :capable of retractionrto aifoldediposition injuxtaposition: of? the supportingimember, with: the: rackdisposedclosely adjacent to'the heel of "theload supporting 'rnean's,and is further capable :of 'expansionl'to a position beyond the iorwarda extremity of 1 the load is-upportingmeans.

It. is an object :of :our "present invention to provide linkage means,between i the 'ivertical supporting. membersand theload engagin 'fikcharacter which will maintain the load/engaging rack gparallel to thesupporting rmember "in I any position ofthe load. engaging rack.

It is another object of :our present.- invention to provide a: mechanismof a this type WhiChz can be extendedto its fully extendedxpositionwitha relatively .-.small strokeof'a hydraulically actuated vpiston, and onewhich-can bevequally well retractedinto .a .foldedposition adjacent tothe rear end of theprojectingload supporting means.

:It is astillfurther object of our present-hm vention to providelaconstruction of this type whichlis sturdy and non-cocking-for-preventinganybinding of..the pivotal connections or. the like.

Now, in order'tovacquaint those skilled .in the art with the manner ofconstructing and .usins. thedevices in accordance with thejprinciples ofour'present invention, we'shall describe in con nection'withtheaccompanying drawings a.preferred embodiment"ofour-invention Inthedrawings:

Figure 1 isa perspective View of the pusher mechanism of our presentinvention, looking diagonally toward an industrial truck to which it-issecured;

Figure 2 is a perspective view of the pusher mechanism of Figure 1,looking diagonally away from the industrial truck to which it issecured;

Figure 3 is a perspective view of the pusher mechanism of Figure 1,looking diagonally down- Wardly;

Figure 4 is a perspective view of theppusher mechanism inretractedposition, as viewed from the front; and

Figure 5 is a perspective view of the pusher mechanism in retractedposition, as viewedfrom one side.

Referring now to the drawings, there is shown the front portion of anindustrialtruck,.indicate'd generally by the referencenumeral Hi,havinga pair of forward driving wheels II. The truck l0 adjacent itsforward end is provided with a vertical mast l2, pivotally mounted forfore and aft tilting-movement adjacent its lower end. The mast 12 has abracket i3 suitably connected to-a hydraulically controlled piston foreffecting tilting movement thereof. .The truck is provided with apowerxplant, such as an internal combustion engine, having pumpmeans-associated therewith for developing fluid under pressure, which isused not only for raising and lowering a load supporting carriage l4,guided'for vertical movement within the mast I2, but also for actuatingthe tilting mechanism l3 and the pusher linkage means, indicatedgenerally at I 5.

The mast I2 is of conventional construction and preferably is formed ofU-shaped channel members [6 and telescoping channel members, mounted forsliding movement therein, within which is slidablylmounted theaforementioned load supporting carriage I4. The telescoping channelmembers, guided in the outer vertical U-shaped channel members l6, areraisedand lowered by means of a hydraulic piston and cylinder assemblyI! mounted intermediate of the channel memberslfi. Suitable chain meansl8,

having connection adjacent their upperends-to the upper ends of thetelescoping channelmembers are provided for raising and lowering theload supporting carriage 14 in a known manner.

Mounted to the forward vertical surface of the load supporting carriage[4 are a pair of vertically spaced frame members is and 2B which extendtransversely of the industrial truck H1. Mounted to the upper edges ofthe upper transverse frame member H), by means -01 inverted hook-shapedmembers 2|, are a plurality of forwardly extending L-shaped loadsupporting forks 22. In place of the forks 22 a solid supporting apronmay be employed or widened forks be used for engaging a load to becarried by the truck it. The particular type of load engaging means isnot pertinent to the present invention and, therefore, the forks 22 areillustrated to show a conventional type of load engaging mechanismemployed with trucks of this type.

Mounted to the foiward vertical surfaces of the frame members I9 and 28,adjacent each side thereof, are vertically extending side frame members23 which are interconnected adjacent their upper ends by means of ahorizontally extending transverse angle frame member 24. The verticalframe members 23 are formed adjacent their upper ends with rearwardlyextending portions 25. Disposed inwardly of each of the rearwardlyextending portions 25, and secured to the rear surface of the horizontaltransverse angle frame member 2 are a pair of bracket members 26.Pivotally mounted between the rear ends of the rearwardly extendingportions 25 and the brackets 2% are the upper closed ends of a pair ofangularly downwardly extending hydraulic piston and cylinder assemblies27. The hydraulic piston and cylinder assemblies 2! are provided foreffecting actuation of the pusher linkage mechanism I5.

Mounted within the confines of the horizontal transverse angle framemember 2 3 are a pair of spaced bearing blocks 28, in which arejournaled the ends of a horizontally extending shaft 29. Fixed to theouter ends of the shaft 28, outwardly of the bearing blocks 23, are apair of forwardly downwardly extending arm members 38 which are providedwith laterally offset portions 3 I, piv otally mounted at their outerends by pin members 32 between the arms of yoke members 33 suitablysecured to the outer ends of the piston rods 34 of the aforedescribedhydraulic piston and cylinder assemblies 21.

The arm members 39 are interconnected, adjacent their outer ends, bymeans of a horizontal transverse brace member 35.

The outer ends of arm members 39 are each mounted, by pin membersbetween the one ends of a pair of link members 32. Each pair of linkmembers 42 extend forwardly and downwardly, and adjacent their lowerends are pivotally mounted by pin members 63 to shoe members A l,slidingly mounted on the lower portions of vertically extending guideframe members Q5. The upper ends of the guide frame members 45 are bentover, and pivotally mounted therebetween by pin members 35 are the oneends of link members 4?, which, at their other ends, are pivotallymoimted, about the pin members at, to the outer ends of theaforementioned arm members so.

Pivotally mounted about pin members 48, adjacent the lower ends of eachof the Vertically extending side frame members 23, are pairs offorwardly upwardly extending arm members 49. Each pair of arm membersto, adjacent their upper ends, are pivotally mounted about pin members50 to shoe members 5i, slidingly mounted on the upper portions oftheaforedescribed vertical guide frame members 55.

Pivotally mounted between the arms of the yoke members 33, at the outerends of piston rods 34, are the one ends of link members 52 which, attheir other ends, are pivotally mounted, about pin members 53, betweeneach pair of arm members 49, intermediate of the ends thereof. Pivotallymounted about the pin members 53, inwardly of the pairs of arm membersit, are link members 54 which extend forwardly and downwardly, and arepivotally mounted, adjacent their lower ends, about pin members 55, tothe lower upturned portions of the vertical guide frame members 45.

Pivotally mounted at their one ends, about pins 50, between each pair ofarm members 59, are a pair of forwardly and downwardly extending armmembers 58. The arm members 58, at their lower ends, are pivotallymounted about pins 59, to the sides of a vertically extendingrectangular load engaging rack 59, which extends transversely of theindustrial truck iii. A pair of link members 56 are pivotally mounted,at their one ends, about pins and at their other ends are pivotallymounted, about pins 5'1, to the arm members 58, intermediate of the endsthereof.

A plurality of horizontally spaced vertically extending strut or bracemembers Q! are suitably secured at their upper and lower ends to theupper and lower portions of the load engaging rack 50. Pivotally mountedto the outermost struts 6!, adjacent the upper end thereof, about pinmembers 52, are the upper ends of a pair of rearwardly downwardlyextending arm members 63. The arm members 63, adjacent their lower ends,are pivotally mounted about the pin members 43 between each pair of linkmembers :32. A pair of link members 94 are pivotally mounted adjacenttheir one ends, about pin members 55, to the arm members 83,intermediate of the ends thereof, and at their other ends are pivotallymounted about the pin members it, adjacent the upper ends of thevertically extending guide frame members The upper and lower ends of thehydraulic piston and cylinder assemblies 21 have connection with aterminal block H through a pair of hose lines 72 and 13, respectively.Fluid under pressure is transmitted to the terminal block H from ahydraulic fluid pump (not shown), through a pair of hose lines 16 and11.

When the load engaging rack 60 and the linkage mechanism I5 are in theposition shown in Figures 1 through 3, and fluid under pressure isadmitted through fluid lines 13 to the lower ends of the cylinders ofthe hydraulic piston and cylinder assemblies 21, the piston rods 34 areretracted thereby causing the arm members 39 to rotate clockwise aboutthe shaft 29. Clockwise rotation of the arm members 30 causes the pairsof link members 42 to urge the shoe members 44 downwardly on thevertically extending guide frame members 45. Retraction of the pistonrods 34 also causes the link members 52 to urge the pairs of arm members49 to rotate counterclockwise about pin members 48. counterclockwiserotation of the pairs of arm members 49 causes the shoe members 51 to beurged upwardly on the vertical guide frame members 45. Upward movementof the shoe members 5 I, together with downward movement of the shoemembers 34, causes the vertical guide frame members 45 to be movedtoward the vertical side frame members 23. Upward movement of the shoemembers 5i causes the arm members 58 to rotate clockwise about pinmembers 58, thereby urging the lower portions of the verticallyextending load engaging rack 66 toward the vertical guide frame members45. Downward movement of the shoe members 44 causes the arm members 63to rotate counterclockwise about pin members 62,

thereby urging the upper portions of the load en-- gaging rack 60' tomove toward the vertical guide frame members 45.

It will be understood that downward rnovement of shoe members 44, upwardmovement of shoe members 5!, clockwise rotation -of arm members and armmembers 58, together with counterclockwise rotation of the pairsof armmembers lfi and the arm members 63, takes place simultaneously. When thepiston-rod -34 =is'in its fully retracted position, as shown in Figures4 and 5, the vertical guide-frame members are disposed substantiallywithin the confines of the vertical sideframe members 23 and the loadengaging rack =60 is disposed adjacent to the forward edges of'thesideframe members23.

'Theindustrial truck l0 may thenbe maneuvered into a position with theforks 22 disposed beneath a pallet supportedload, after which the forks22 may be raised, together with-the pallet and load, and the'truck iiidriven to the desired location where the load is to be deposited.

While fluid under pressure is admitted to the upperends of the hydraulicpiston and cylinder assemblies 2?, through the hose lines 12, the truckII] is simultaneously backed away. Fluid under pressure, admitted to thehydraulic piston and cylinder assemblies 2?, causes the piston rods 34to be extended, thereby causing the arm members 3!! to rotatecounterclockwise which causes the shoe members 45 to be urged upwardlyon the vertical guide frame members 45. When the piston rods 34 areextended the link members 42 are caused to urge the pairs of arm members49 to rotate clockwise about pin members 48, thereby causing shoemembers 5! to be urged downwardly .on the vertical guide frame members45. Downward movement of, the .shoe members 5| and upward movementof'the shoe members 4 1 causes the vertical guide frame members 45 to bemoved away from the vertical side frame members 23. Downward movement of.the shoe members 5! also causes arm members 58 torotatecounterclockwise about pin members 59, thereby extending the lowerportion of the load engaging rack 69. Upward movement of shoe members 44causes the arm members 53 to rotate clockwise about pin members 62,thereby extending the upper portion of the load engaging rack 60. Afterthe piston rods 34 have been fully extended the load engaging rack 89,together with the linkage mechanism l5, assumes the position shown inFigures 1 through 3.

Small movement of the piston rods 34 produces, through theaforedescribed linkage arrangement, a relatively large movement of theload engaging rack 60, thus providing for rapid extension and retractionof the latter.

With the provision of the link members 4', 5 5, 56, and 54 the loadengaging rack 5|! is prevented from tilting rearwardly when the upperportion of the rack M is engaged with a, load to a greater extent thanthe lower portion of the rack. The link members 4?, 54, 55, and 64 arealso provided for supporting the guide frame members 45 during movementtoward and away from the side frame members 25.

While we have shown and described what we believe to be a preferredembodiment of our present invention, it will be understood that variousmodifications and rearrangements may be made therein without departingfrom the spirit and scope of our invention.

We claim:

1. A pusher mechanism for an industrial truck having a load supportingcarriage including load 6 supporting means :extending forwa-rdly ef thetruck comprising, a supporting frame adapted to be mounted onsaidcarriage to extend transversely of and at-the inner'end :ofsaid'load supporting means, a vertical load engaging rack extendingtransversely of *said load supporting means, first arm meanspivotally-'mounte'cbat' one end adjacent'the upper end of sa-idsupporting frame, second arm means pivotally mounted at one endadjaoentthe'upper-end of said rack,

first shoe -means, said first and second arm means extendingdownwardlytoward each other and being pivotally connected adjacent their otherends to said first shoe-means, third arm means pivotally mounted at oneend adjacent the lower end of said supporting frame, fourth arm meanspivotally mounted at one end -adjacentthe lower end of said rack, secondshoe means, said third and fourth arm means extending upwardly towardeach other-and=-being pivotally connected adjacent their other ends tosaid-second shoe means, said first and second shoe means being slidablymounted-on substantially vertically extending guideframe'meana'an'dmeans for pivoting said first arm means whereby said rack is extendedand-retracted over said load supporting means.

'2. The combination'of "claim 1 wherein said last named meanscomprisesfiuidpressure actuated means carried bysaidsupporting frame.

3. The combination 'of'claim 1 including link means between said firstarm means "and said guide frame means and" betweensaid second arm meansand said guide frame means.

4. The combination 'ofclaim 3 including-link meansbetween said third armmeans and said guide frame means an'dbetween said fourth "arm means andsaid guide framemeans.

"5. The "combination of claim '1' including link means betweensaid thirdarmmeans'and'said guide frame means and betweensaidfourtharm means andsaid guide frame means.

"6. A pusher "mechanismfor an industrial" truck having a load supportingcarriage including load supporting means extending forwardly of thetruck comprising, a supporting frame adapted to be mounted on saidcarriage to extend transversely of and at the inner end of said loadsupporting means, a vertical load engaging rack extending transverselyof said load supporting means, a horizontal shaft carried by saidsupporting frame adjacent the upper end thereof, first arm means mountedat one end on said shaft, second arm means pivotally mounted at one endadjacent the upper end of said rack, first shoe means, said first andsecond arm means extending downwardly toward each other and beingpivotally connected adjacent their other ends to said first shoe means,third arm means pivotally mounted at one end adjacent the lower end ofsaid supporting frame, fourth arm means pivotally mounted at one endadjacent the lower end of said rack, second shoe means, said third andfourth arm means extending upwardly toward each other and beingpivotally connected adjacent their other ends to said second shoe means,said first and second shoe means being slidably mounted on substantiallyvertically extending guide frame means, and means for pivoting saidfirst arm means whereby said rack is extended and retracted over saidload supporting means.

7. The combination of claim 6 wherein said last named means comprisesfluid pressure actuated means carried by said supporting frame.

8. The combination of claim 6 including link means between said firstarm means and said guide frame means and between said second arm meansand said guide frame means.

9. The combination of claim 8 including link means between said thirdarm means and said guide frame means and between said fourth arm meansand said guide frame means.

10. The combination of claim 6 including link means between said thirdarm means and said guide frame means and between said fourth arm meansand said guide frame means.

11. A pusher mechanism for an industrial truck having a load supportingcarriage including load supporting means extending forwardly of thetruck comprising, a supporting frame adapted to be mounted on saidcarriage to extend transversely of and at the inner end of said loadsupporting means, a vertical load engaging rack extending transverselyof said load supporting means, a horizontal shaft carried by saidsupporting frame adjacent the upper end thereof, first arm means mountedat one end on said shaft, second arm means pivotally mounted at one endadjacent the upper end of said rack, first shoe means, said first andsecond arm means extending downwardly toward each other and beingpivotally connected adjacent their other ends to said first shoe means,third arm means pivotally mounted at one end adjacent the lower end ofsaid supporting frame, fourth arm means pivotally mounted at one endadjacent the lower end of said rack, second shoe means, said third andfourth arm means extending upwardly toward each other and beingpivotally connected adjacent their other ends to said second shoe means,said first and second shoe means being slidably mounted on substantiallyvertically extending guide frame means respectively at the lower andupper portions thereof, first link means pivotally mounted at one end tosaid first arm means intermediate of the ends thereof and pivotallymounted at the other end to the upper end of said guide frame means,second link means pivotally mounted at one end to said second arm meansintermediate of the ends thereof and pivotally mounted at the other endto the upper end of said guide frame means, third link means pivotallymounted at one end to said third arm means intermediate of the endsthereof and pivotally mounted at the other end to the lower end of saidguide frame means, fourth link means pivotally mounted at one end tosaid fourth arm means intermediate of the ends thereof and pivotallymounted at the other end to the lower end of said guide frame means,said first arm means having laterally extending leg means, fifth linkmeans pivotally mounted at one end to said leg means and pivotallymounted at the other end to said third arm means intermediate of theends thereof, and means having connection with said leg means forpivoting said first arm means whereby said rack is extended andretracted over said load supporting means.

12. The combination of claim 11 wherein said last named means compriseshydraulic piston and cylinder means carried by said supporting frame.

E. RYAN BACKOFEN. ELMER J. DUNHAM. SIDNEY R. SKELLENGER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 513,553 Blakely et al Jan. 30-, 1894 1,977,785 Wheelock Oct.23, 1934 2,176,636 Meacham Oct. 17, 1939 2,496,039 Crawford Jan. 31,1950 2,691,931 Dunham et a1. July 1, 1952 FOREIGN PATENTS Number CountryDate 474,968 Germany Apr. 17, 1929 323,812 Italy Jan. 9, 1935

